24 Rhodora [FEBRUARY 
antecedents are to be sought in the normal composition of the plant 
body. These and other categories of abnormalities are of interest to 
the student of evolution. It is my purpose to deal here with only, 
one kind of changes, of which I have endeavored to point out the 
real character. It would be a profitable labor to discover the modes 
and limits of morphic translocation as exhibited in monstrous forms. 
At present I shall merely add to this part of my remarks a few words 
upon the weight of teratological evidence in certain recent discussions 
of homologies. 
CRITICISM OF RECENT ARGUMENTS FROM TERATOLOGICAL PREMISES. 
— In the egg apparatus of the embryo sac in flowering plants are 
three cells, of which one is larger than its two neighbors. The large 
cell is the egg, the smaller ones are the synergids. The egg-cell is 
held to be the last vestige of an archegonium, the accessory parts of 
which have been lost — unless the synergids represent the parts. 
What portions of the original archegonial or prothallial arrangement 
the synergids represent is wholly obscure. But it has been found 
that occasionally one of the synergids becomes capable of fertiliza- 
tion, 7. ¢, becomes an egg cell. Some writers have held this 
exceptional behavior to show that the synergids, as potential egg- 
cells, are degenerate egg-cells in fact, historically coórdinate with the 
egg proper. Again, in the venter of the archegonium of Pinus there 
are two cells. One is large and destined to be fertilized, the egg. 
The other, or ventral canal cell, is small and transitory. Rarely, 
however, the latter cell becomes enlarged and in all visible respects 
egglike. This abnormality is regarded by Coulter and Chamberlain,’ 
as strong evidence in favor of the conclusion that “the ventral canal 
cell represents an abortive egg, which is occasionally organized as an 
egg, and which may rarely function as one.” In the cones of the 
Abietaceae the ovuliferous scales have sometimes been found more or 
less perfectly replaced by leaf-bearing shoots. From this it has been 
argued? by Braun, Caspary, Parlatore, Oersted and others that the 
fertile scale is morphologically a reduced branch in the axil of the 
sterile one. 
As far as the teratological facts themselves are concerned, without 
the aid of the more important collateral evidence, these three cases 
! Seed Plants, p. 87. 
? Summary and references in op. cit., ch. LII. 
